"Hey, doc,'' the man repeats. "You now what my medication is? Drink as much as I can!''

Both laugh heartily, and Turnbull gives him a friendly slap on the back. This is not a place for the prudish.

It is a weekday morning in Ottawa, Canada's capital, and Turnbull has just arrived at a Salvation Army shelter for the homeless, one of three he will visit this day. The shelters are part of a program that is saving millions of dollars by keeping homeless drunks and drug addicts out of the hospital.

"Before we started, some of these people would have been in the emergency room daily,'' says Turnbull, chief of staff at Ottawa's largest hospital.

As Congress wrestles with health care reform, much attention has been focused on Canada's system of universal coverage. Even the poorest of the nation's 33 million citizens are entitled to doctor visits and hospital care at government expense.

Canada spends 10 percent of its gross domestic product on health care, compared with 15 percent in the United States. However, Canadian health care costs are soaring as the population ages. Hence the push for money-saving programs like Ottawa's Inner City Health Care, largely funded by the Ontario Ministry of Health.

"Both the Canadian and American systems have trouble getting care for the poor, the disabled and the psychiatric,'' Turnbull says, "but I think the organization and delivery of care is easier when you have a public system.''

• • •

Turnbull, an internist who bears a slight resemblance to comedian Robin Williams, makes the shelter rounds twice a week.

The first stop is a place almost unimaginable in the United States — a hospice for the homeless. He steps into a small but sunny room where Dr. Tara Tucker strokes the shriveled arm of a 56-year-old musician with a long history of drug abuse. Esophageal cancer has spread to his abdomen.

Canada's controversial pipe-and-needle exchange programs started in 1989 in Vancouver, where addicts are permitted to inject at a supervised site. The city of Ottawa never sanctioned injections but even the pipe exchange was too much for city councillors, who killed the program in 2007. It has continued with funding from the Ontario government.

Everyone at the Salvation Army is up and about, though several flock to Turnbull with minor ailments. For a severely abscessed toe he prescribes a drug that normally costs $500; there is no charge to the sufferer, who is covered under Ontario's prescription drug program for the disabled, low income and people 65 and older.

Others complain of generalized pain. Some of the shelter's denizens have been hooked on powerful opiates like OxyContin and clearly want more.

For most of those he treats, Turnbull can bill the Ontario Health Insurance Plan. He donates the money to the Inner City program so it can help more clients and buy over-the-counter drugs, which are not covered by the government. Turnbull prescribes one — Sinutab — for a barrel-chested man with a scraggly ponytail.

"I really appreciate the help you give me, doc,'' he says. "Really.''

• • •

The final stop is a shelter that runs Ottawa's Managed Alcohol Program, currently caring for 25 chronically homeless drunks.

From 9 a.m. to 9 p.m. participants get precisely 5 ounces of wine every hour. It sounds like a staggering amount.

"That's about one-ninth of what they would take on the street,'' Turnbull says.

Indeed, no one looks or acts drunk. Several have been detoxed to the point where they go fishing, have pizza parties and work odd jobs around the shelter or at a nearby church. One, a talented Aboriginal artist, even has an agent and write-ups in the local paper.

As he mingles easily with what many would consider the dregs of Canadian society, Turnbull, 58, is at the peak of his own profession.

Next year he takes over as president of the 68,000-member Canadian Medical Association. Unlike some of his predecessors, who advocated a bigger role for private insurance as in the United States, Turnbull is firmly committed to government-funded universal coverage.

"I think his election (as association president) symbolizes in many ways the split within Canadian medicine about our system,'' says Dr. Michael Rachlis of Toronto, an expert on health care policy. "He's more the wave of the future as younger physicians who've grown up with the system are trying to figure out how to make it better rather than how to get rid of it.''

The Inner City program saved an estimated $3.5 million last year by keeping street people out of the hospital. But in Canada's egalitarian system some do end up there, including one Turnbull fondly recalls.

"It was a charming transvestite named Mandy. She was having trouble with her hair, and the nurses just loved doing her hair and her nails. There was a politician in the next bed ringing the bell and saying, 'I can't get any service!' "